[sdiy] Pulser & Ring Mod PCBs from by Music Easel adaptations available; New Year's Eve Special

[Dave Leith]

Has anyone build these circuits?


I have a question about the pulser board. Does the cv output
(downwards ramp) maintain a sawtooth ramp (1) shape at the faster
speeds or does the top flatten out (2).

1, Normal cv (subaudio rate)
.           .            .            .
   .        .   .        .    .       .   .
      .     .      .     .       .    .      .
         .  .         .  .          . .         .
            .            .            .            .


2. does one get higher speeds like this?
....        ....         ....         ....
   .        .   .        .    .       .   .
      .     .      .     .       .    .      .
         .  .         .  .          . .         .
            .            .            .            .

thanks dave


On Fri, Dec 31, 2010 at 3:13 PM,  <lanterma at ece.gatech.edu> wrote:
> So, I was able to squeeze out a little bit of time over break to finish off to do some building & testing of my Buchla Music Easel adaptations.
>
> 1) I am pleased to say that Revision 1 of the Pulser & Inverter board works! My pulser pulses! It just works, no jumpering or trace cutting or other crazyness is necessary. It's a fun CV source; the pulse rate itself is CV controllable, and it can go way up into the audio range.
>
> 2) I haven't had time to finish testing Revision 1 of the Balanced Modulator myself, but a kind, hard-working beta tester put it together and send in the following bug report:
>
> "The VCA and crossfader circuits both worked perfectly right away but the balanced modulator was giving me trouble until right now. While most of the pin swaps happened correctly, pin 6 of IC 2  was coupled to the LED of vactrol 3 rather than the junction of the photocells of vactrols 3 and 4. I cut the errant trace and installed a couple of jumpers and I now have a functional balanced modulator. The circuit works well with TL072. Thanks for following up. I have only played with the ring mod for about 5 seconds, but I already love the ancillary circuits."
>
> -----------------
>
> Here are the docs of the original "Rev 0" boards:
>
> http://users.ece.gatech.edu/~lanterma/buchla/boards/mea_pulser
>
> http://users.ece.gatech.edu/~lanterma/buchla/boards/mea_balmod
>
> I will get some "Rev 1" docs up soon. Most of it will be the same; the basic difference, of course, will be in the "Errors" section.
>
> -----------------
>
> I've got seven of each of the above sitting on my bench, wanting some love.
>
> $15 for a Pulser Rev 1 board. $10 for a Balanced Mod Rev 1 board (a fully working revision of this, if such ever happens, will go for $20, so I'm giving a 50% discount on these since they require the cutting and jumpering mentioned above; they're also a bit of a risk since I haven't had time to test it myself).
>
> $4 flat shipping + handling, to wherever.
>
> NEW YEAR'S EVE SPECIAL: Order at least one of each by midnight, and get free shipping + handling!
>
> E-mail me telling me how many of each you want, and then I will give you the heads up to paypal me. I don't have many of each, so I want to make sure I have boards left in the stack before you paypal me.
>
> - Aaron
>
> P.S. Sorry I don't have any idea when I'll do a yet another revision of the ring mod board to fix the above bug...
>
> P.P.S. Yes, I do plan to do another pcbcart run, with LPGs, Envelope Detectors, Preamps & Envelope Detectors, Pulsers, and who knows what else. I will announce in the usual places when that happens.
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